Method and device for solid phase microextraction and desorption

Abstract

A device for carrying out solid phase microextraction is a fiber contained in a syringe. The fiber can be solid or hollow. The syringe has a barrel and a plunger slidable within the barrel, the plunger having a handle extending from one end of the barrel. A hollow needle extends from an end of the barrel opposite to the plunger. The fiber is contained in the needle. When the plunger is depressed, the fiber extends beyond a free end of the needle and when the plunger is in a withdrawn position, the fiber is located within the needle. The syringe protects the fiber from damage. When it is desired to analyze a sample in a bottle having a septum, the needle is inserted through the septum and the plunger is depressed so that the fiber will extend into the sample. After one or two minutes, the plunger is moved to the withdrawn position so that the fiber will return to the needle and the syringe is withdrawn from the sample bottle. The syringe is then inserted through a septum in a gas injection port of a gas chromatograph. The plunger is again depressed so that the fiber will extend into the gas chromatograph and an analysis of the components on the fiber is carried out. Then, the plunger is moved to the withdrawn and the syringe is withdrawn from the injection port. Previously, samples were analyzed using liquid-liquid extraction or using cartridges. Both of these methods are relatively expensive and time consuming. Both of these methods also require the use of solvents which can be difficult and expensive to dispose of.

Description

[0001] This is a divisional application of application Ser. No. 09 / 226,153 filed Jan. 7, 1999, which is a continuation application of application Ser. No. 08 / 826,682 filed Apr. 7, 1997, which is a continuation application of application Ser. No. 08 / 306,435 filed Sep. 19, 1994 which is a continuation-in-part Application of application Ser. No. 07 / 934,736 filed Oct. 10, 1992.[0002] 1. Field of the Invention[0003] This invention relates to a method and device for solid phase microextraction and analysis and, in particular, relates to microextraction and analysis being carried out using various types of a single fiber which can be coated with various materials or uncoated.[0004] 2. Description of the Prior Art[0005] Presently, in the organic analysis of environmental samples which involve the separation of components of interest from such matrices as soil, water, fly ash, tissue or other material, liquid extraction is traditionally used as the separation process. For example, water samp...

AI Technical Summary

Problems solved by technology

Methods based on solvent extraction are often time consuming, difficult to automate and are very expensive since they require high purity organic solvents and these organic solvents are expensive to dispose of.

Further, the organic solids usually have high toxicity and are difficult to work with.

In addition, the extraction processes can be highly non-selective.

Therefore, sequential chromatographic techniques must sometimes be used to separate complex mixtures after extraction, significantly increasing the overall analysis time and the cost.

However, solid phase extraction continues to use solvents and often suffers from high blank values.

Further, there is considerable variation between the products offered by different manufacturers and lot-to-lot variation can be a problem when carrying out solid phase extraction procedures.

Steps involving the use of organic solvents are the most time consuming.

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